Setup PLC to accept input register high to count Done! Setup PLC to accept output register high to count Done! Setup 4-bit register to output to Nixie driver to show numerical count on Nixie tube (Single Digit) Done! Setup secondary 4-bit register to output to Nixie driver to show numerical count on Nixie tubes (Double Digit) Done! Translate current count to 2x(4-bit) registers. Done!